As already known, in recent years a new steering system called SuperSteer™ has been introduced by the Applicant.
In this SuperSteer™ steering system, during the steering step, each hub relating to each front wheel rotates around its own axis, synchronically to the whole front axle, which also rotates around a pin by a determined steering angle.
This provides the tractor with an optimum manoeuvrability and with a drastically reduced turning radius.
However, the SuperSteer™ system shows some drawbacks, the main one being that, during the steering of the front wheels, the whole front axle rotates around a vertical axis. This implies a side skid of the whole tractor, which is unwelcome both at low and high speeds.
In particular, some side skids occurring during the steering at low speeds can be a problem with regard to the control of the implements coupled before or behind the tractor.
In fact, even at low speeds, said side skids, due to the SuperSteer™ steering, are rather fastidious, in particular when the tractor must operate with a certain accuracy passing among the rows of plants in vineyards and orchards, or with front loaders. In fact, the side skids could lead to unwelcome movements of the implements coupled to the tractor, thus causing the crashing of the same implements against the row posts or against the plants, with resulting relevant damages.
Therefore, the main aim of the present invention is providing a steering system for motor vehicles, in particular for agricultural machines, which is free from the aforesaid drawbacks and, at the same time, can be provided with a kind of SuperSteer™ steering effect.
More precisely, in the steering system for motor vehicles object of the present invention, the wheel steering and the front axle steering are separated and mutually independent, at least until they reach some values of the steering angles of the front wheels previously determined by the manufacturer; once these pre-determined values have been surpassed, the front axle and the wheels are synchronically steered, just like a traditional SuperSteer™.
A further aim of the present invention is providing a steering method for motor vehicles which allows to overcome the aforesaid drawbacks.
According to the present invention it is therefore realized a steering system for motor vehicles and a corresponding steering method, according to what claimed in the independent claims, or in any one of the claims directly or indirectly dependent from the independent claims.